High Carbon Prestressed Concrete Steel Strand 12.7mm Low Relaxation 7 Wire Prestressing Strand
Prestressed steel strands are manufactured from high-strength carbon steel wire rods through cold drawing, twisting, and stabilization processes. Each strand consists of 7 high-strength steel wires with a diameter of 15.2mm and tensile strength of ≥1860MPa. Produced in strict compliance with GB/T 5224-2014 standards, these strands feature surface treatments including hot-dip galvanizing or epoxy coating for excellent corrosion resistance. The relaxation rate is ≤2.5%, ensuring long-term stress maintenance.
| Steel Strand Structure | Nominal Diameter Da /mm | Dia Tolerance /mm | Strand Nominal Cross-Sectional Area Sn/mm² | Approx. Weight per meter(g/m) | Range(extened)% of core wire's diameter not less than |
|---|---|---|---|---|---|
| 1x7 | 9.50 (9.53) | +0.30 -0.15 | 54.8 | 430 | 2.5 |
| 1x7 | 11.10 (11.11) | +0.30 -0.15 | 74.2 | 582 | 2.5 |
| 1x7 | 12.70 | +0.30 -0.15 | 98.7 | 775 | 2.5 |
| 1x7 | 15.20 (15.24) | +0.30 -0.15 | 140 | 1101 | 2.5 |
| 1x7 | 15.70 | +0.40 -0.15 | 150 | 1178 | 2.5 |
| 1x7 | 17.80 (17.78) | +0.40 -0.15 | 191 (189.7) | 1500 | 2.5 |
| 1x7 | 18.90 | +0.40 -0.15 | 220 | 1727 | 2.5 |
| 1x7 | 21.60 | +0.40 -0.15 | 285 | 2237 | 2.5 |
| Grade | Nominal Diameter (mm) | Tolerance (mm) | Area of Section (mm²) | Weight of strand (kg/1000m) | Minimum Breaking Load (KN) | Minimum Load at 1% extension (KN) | Elongation not less than (%) | 1000Hrs Relaxation Value Not More Than |
|---|---|---|---|---|---|---|---|---|
| 250 | 9.53 | ±0.41 | 51.61 | 405 | 89.0 | 80.1 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 250 | 11.11 | ±0.41 | 69.68 | 548 | 120.1 | 108.1 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 250 | 12.70 | ±0.41 | 92.90 | 730 | 160.1 | 144.1 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 250 | 15.24 | ±0.41 | 139.35 | 1094 | 240.2 | 216.2 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 270 | 9.53 | +0.65 -0.15 | 54.84 | 432 | 102.3 | 92.1 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 270 | 11.11 | +0.65 -0.15 | 74.19 | 582 | 137.9 | 124.1 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 270 | 12.7 | +0.65 -0.15 | 98.71 | 775 | 183.7 | 165.3 | 3.5 | 2.5 (70%) / 3.5 (80%) |
| 270 | 15.24 | +0.65 -0.15 | 140.00 | 1102 | 260.7 | 234.6 | 3.5 | 2.5 (70%) / 3.5 (80%) |
- Ultra high strength and toughness: Breaking force ≥260kN, elongation ≥3.5%, maintaining structural integrity under extreme loads
- Low relaxation characteristics: Low-temperature stabilization technology reduces long-term stress loss by 40% compared to ordinary steel strands, ensuring long-term structural safety
- Strong corrosion resistance: Hot-dip galvanized layer thickness ≥275g/㎡, epoxy coating adhesion ≥10MPa, suitable for harsh environments including ocean and salt alkali conditions
- Convenient construction: Lightweight and flexible single bundles facilitate easy threading and tensioning on site, increasing construction efficiency by over 30% compared to traditional steel bars
Widely used in large-span bridges (suspension bridges, cable-stayed bridge box girders), high-rise buildings (super high-rise shear wall structures), hydraulic engineering (dams, prestressed anchoring of aqueducts), rail transit (ballastless track slabs for high-speed rail), and geotechnical anchoring (slope support, foundation pit anchoring) and other fields.
Our steel wire rope meets international production standards and has obtained multiple certifications including:
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